One in three people will contract cancer in their lifetime. Compared to the early 20th century cancer was seen as a rare disease. In Hong Kong the number of new cancer cases are rises by on average 2% per year, the most common cancers being lung, colorectal, Liver and stomach. Factors like urbanisation, adoption of the western diet (trans Ffats and sugar), increasing pollution and an aging population all influence the incidence of particular cancers in Hong kong.